Internal keyway grinder



May 18, 1943 G. B. CARROLL 2,319,582

INTERNAL KEYWAY; GRINDER l Filed July 7, 1941 4 Sheets-Shea? 2 53 'sa f G. B. CARROLL.

INTERNAL KEYWAY GRINDER lullllllllllnllllfnwllynnl.

'Filed July '7, 1941 May R8, 1943 G. E. CAJRRQLL. 2,31%,582

INTERNAL KEYwAY GRINDER l Filed July 7, 1941 4 sheets-sheet 4 /o.5" l

kwa/W70@ @ay 7a', (Tarma/f R324: fije/'WQ' raiemeaiviay 1s, 1943' o'FFiCE INTERNAL KEYWAX Gnmmza Guy B. Carroll, Minneapolis, Minn. Application July v, 1941, serial No. 401,316

32 Claims.

My invention relates to improvements in grinders and more particularly to a grinder for grinding internal keyways, internal gears and the like.

While the invention is intended for general use, it is especially well adapted for grinding internal keyways in the cylindrical barrel of a hydraulic pump as used -by the Navy for gun control.

`It is well known that these pump barrels are first made undersize, then hardened', which results in warpage, and thereafter finished to given dimensions. The pump barrel has an axial bore for a pump shaft that extends axially and loosely therethrough. The pump shaft is provided with two diametrically opposite keys that are fitted in keyways in the pump barrel aridit is such keyways that we have to consider in the presentv application.

It is well known that at presentinternal keyways in a pump barrel are individually finished portion of the machine, 'on an enlarged scale. and also showing the pump barrel and the means for mounting the same thereon, and the means i` for aligning the same Fig. 3 is a-pian view ofthe parts shown in Fig. 2;

by hand to lit the keys on a particular pump shaft, which isa tedious and expensive operation. Each pump barrel and its shaft h ave marked thereon like identifying characters so that, when separated, they can be reassembled with the keys on a pump shaft in the keyways of a pump barrel finished therefor. The keys on no two pump shafts will fit the internal keyways in'a given pump barrel and hence are not interchangeable.

The object 'of this invention is to grind internal keyways and the like to predetermined sizes.

Another object of this invention is to grind internal keyways in pump barrels to predeter mined sizes and all exactly alike andhence interchangeable, and with their center lines concentric with the pump barrels.

Other objects of the invention will be apparent from the following description, reference being had to the accompanying drawings. v

.To the above end. generally stated, the invention consists of .thenovel devices and combina` Fig. 4 is an end view of the parts shown in' Fig. 2:

` Flg. 5 is a view partly in side elevation'and partly in section taken on the line 5-5 of Fig. 4;

Fig. 6 is a View of v aligningvblock in transverse vertical section:

Fig. 7 is a fragmentary view showing a modication of the pump barrel aligning device:

Fig. 8 is a plan view of the grinder. some parts 'being broken away;

Fig- 9 iS fragmentary View principally in horizontal section taken on the line 9 9 of Fig.

Fig. 10 is a fragmentary view principally in section taken on the line IIIe-l0 of Fig. 1l;

Fig. 11 is a view of the grinding unit partly in v y vside elevation and partly in longitudinal central vertical section;

Fig..12 is a view of the control head removed v from the grinder, some parts being broken away tions of devices hereinafter described and delined in the claims. l l

In the accompanying. drawings, which illus? trate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. l is a view partly in front elevation and partly in section showing the invention mounted Aon a' machine of the typeof a surface grinder and also showing a pump barrel mounted on said machine;

Fig. 2 is a fragmentary view of the lefthand 65 and sectioned Fig. 13 is a. detail view partly in elevation and partly in section taken on the line lI- il of Fig. 8;

Fig. 14 is a view principally in end elevation with some parts sectioned on Ithe line M-il of Fig. l1 and with other parts broken away;

Fig. l5 is a view principally in section taken on theline IS-IB ofFlg. 11;'

Fig. 16 is a fragmentary detail view partly in side elevation and partly in section taken on the line|6-I6ofFig.8;

Fig. 1'1 is a front end elevation of the control head, some parts being broken away and other parts being sectioned;

Fig. 18 is a detail view partly in elevation and partly in section taken on the line l-il of Fins; i

-Flgf19 is a view in front elevation, on an enl i larged scale, of one of the driving belt tighteners and directional pulleys and a section of the belt.

l shown by means of broken lines; and

Fig. 2o is e detail view paruy m plan and partly in section taken on vthe line Il-Il of Fig. l5;

' The invention is mounted on a. machine of the type oi' a surfacegrinder and of the parte thereof, itis important to note the base or bed 2l, on which a table '22 is mounted in ways 2l to be reciprocated endwise hydraulically, as indicated tons, only the rods 4| of which are shown.

. head 32.

at 24; the slide 25, mounted in ways 26 atthe back of the machine for vertical movement; the

screw 21 and a co-operating nut, not shown; and l the connections for operating the nut including a hand wheel 28. In the toprof the table 22 are the customary parallel T-slots 29 that extend longitudinally thereof.

The improved grinder includes a horizontally 4disposed cylindrical housing 3|) having an inte- .gral supporting bracket 3| rigidly bolted to the side on the face thereof. This housing` 30 is open at both ends and its longitudinal axis is parallel to the upper face of the table 22. A

cylindrical control head 32 is rotatably mounted in the housing 30 with a close working fit' and with its axis coincident with the axis of said housing. This control head 32 is held against movement in the. housing 30 by an annular flange 33 on one end thereof, and a vnut 34 on the other end of said head. Said ange 33 and nut 34 impinge against the ends of the housing 36 as bases of resistance.

The control head 32 is rotated in the housing 30 one hundred eighty degrees, by a vertically movable rack 35 and co-operating gear teeth 36 in the control head 32 at the longitudinal center thereof. This rack 35 works endwise in a passageway 31 therefor inthe housing 30. A` stop member 38 on the flange 33 of the control head 32 and a pair of co-operating stop lugs 39 on the housing 30 limit the rotary movement of the control head 32 andl permit a rotary movement thereofof exactly one hundred eighty degrees.

'Ihe rack 35 is endwise reciprocatedhydraulically,

by a pair of cylinders 40 an co-operating pis'- These cylinders 40 are secured to the slide 25 below the table 22. By reference to Fig. 14 it will be noted that the rack 35, at its lower end, is connected to one of the piston rods 4| and a rod 42 connects the two piston rods 4|, the one to the ri other. Formed in the control head 32 is a rela- .control head 32 and has sliding contact with the upper and lower surfaces of said control box in the passageway 43. Oblique keys and co-operating keyways 46 in the contacting surface of the l control head 32 and the control box 44 are provided for imparting lateral movement in a horizontal plane A secondfcontrol box 41 is mounted in the control box 44 for vertical adjustment and has sliding contact with the vertical internal walls of the control box 44. Oblique keys and co-operating keyways 48 in the contacting surfaces of the control boxes 44 and 41 are provided for imparting vertical movement to the control box 41 in the controlbox 44. The control box 41 extends outwardly of the ends of the control box 44,. and formed with the right-hand end of the control box 41 is a control disk 49 that extends transversely thereof. Both control boxes to said control box in the control .terior of the control box 41 is round in crosssection.

Mounted in the control box 41 is a long tubular shaft 50 'held by a key 50 against rotation therein. vOn the right-hand end of the shaft 50 is an annular flange 5| that engages the control box 41 at its respective end, and a nut 52 on the shaft' 50 engages the other end of said box. The flange 5| and nut 52 hold the shaft 5U against axial movement in the control box 41. The shaft 50 outwardly of the control box 41 and the nut 52 is reduced in diameter and extends materially'to the left from the control box 41 and this section or extension of the shaft 50 is designated by the numeral 53.` In the actual usage of the improved grinder,.the same will be pro- -vided with a plurality of shafts 50 of the same diameter to llt the passageways therefor in the control box 41, but having extensions 53 of different diameters for different types and sizes of work.

A grinding wheel 54 is mounted on the outer end portion of the shaft yextension 53, which is cut away as -indicated at 55, to afford clearance forsaid wheel. Formed with the internal wall of the shaft extension 53 is a stub shaft 56 that extends diametrically and horizontally therethrough. The grinding wheel 54 is mounted on a relatively large tubular hub 61 and is clamped thereon between a flange 53 integral with said hub and a loose flange and a nut 59. the latter having screw-threaded engagement with the hub 51. -The hub 51 extends axially over the shaft A56 and is mounted thereon by ball bearing asextends inwardly from the flange 58, affords a pulley 63.l It willbe noted that the projected longitudinal axes of the shaft 50 and its extension 53'extend diametrically through the grinding wheel 54 relatively close to the inner face thereof. The axis about which the grinding wheel 54 rotates is coincident with the longitudinal axis of the shaft' extension 53 and perpendicular thereto. A plate 64 affords a closure for the outer end portion of the shaft extension 53 and is removably secured thereto by a suitable clamping device, not shown.

The grinding Wheel 54 is driven by a4 belt 65 from an electric motor 66. The belt 65 is flat but, of course, may be a v belt. This motor 66 is mounted on a bracket 61 rigidly secured to the right-hand end of the tubular shaft 56. A pulley 68, encircling the motor 66, is keyed to the armature shaft thereof and aligned with the pulley 63. The pulley 68 is relatively large in respect 44 and 41 are open at their ends and the in- 7 to the pulley 63 and the belt 65 runs over said two pulleys and longitudinally through the shaft 50 and its extension 53.' The belt 65, at the righthand end of the shaft 5U, runs over two rolls 69 that act as belt tighteners and directional rolls for said belt. These rolls 69 are journaled in ady justable bearing brackets 10 secured to the control disk 49by-machine screws 1| that extend 'through slots 12 in said bracket.

grinding wheel I ismoved laterally toward or from said axis. To move the control box 44 laterally by sliding the same obliquely in the control head 02 by means of the keys and cooperat" ing keyways l0, the following automatic and manually controlled connections are provided.

' to wit: a long screw shaft 13 that extends parallel to the axis of the control head 32 is turnably mounted in a right-hand bearing 14 and abifurcated left-hand'bearing 15 o n the housing 30. m Integral with the left-hand end of the shaft 13 is a pair of jaws 19 between which the control disk 45 extends and is held thereby against lateral movement, but is free for edgewise move- 'ment therebetween. 'I'he manual .connections for moving the screw shaft 13 endwise includes. a nut-acting bevel gear 11 on the screw-threaded lend portion of, the shaft 13 to the left" ohlthe bearing 15. A bevel gear 18' meshing with he bevel gear 11 is rigidly'secured tothe inner nd`20 said shaft may be turned. Y y 25 The automatic cnnnections 'for moving the Wheel ll having Screw-threaded engagement screw shaft 13 endwlse includes a nut-acting ratchet wheel 82 held between the prongs ofthe bearing against axial movement on said shaft. A step of rotary movement is/imparted to the .ratchet wheel 92, at the limit of the endwise movement of the rack when rotating the control head 32, by a spring-pressed pawl 89 on `a pawl carrier 09. This pawl carrier Sli-is bifurcated and straddles the pawl 83 and the prongs 35 thereof are pivoted to the shaft 13 between the prongs of the bearing 15. The pawl carrier 89 is yieldingly held on a vertically adjustable -stop pin 85, having screw-threaded engagement with the housing 30. by a coiled spring 00 attached to o said carrier and anchored to the housing 30. I

The pawl carrier 8d is lifted from the stop pin 05, toimpart a step of rotary movement to the ratchet wheel 92 by means of thepawl 88, by a laterally projected lug 9i on the lower end por- .45

automatic connections are provided, to wit: a

long square bar iid, extending parallel to the axis of the control head 92, is slidably'mounted in a way 89 onthe underside of the housing 00 and held therein by transverse plates 90. A. pair of baril, engages the control disk d5 on opposite sides thereof and'thereby holds said disk against lateral movement but permits free edgewise movement of the disk 95 therebetween. The bar 00 is endwise reciprocated, to successively raise and 60 lower control box 91 and hence the grinding wheel 54 by hydraulic means including a pair of cylinders 92 and co-operating pistons, only the rods 93 of .which are shown. The cylinders 92 are mounted on the slide 25. One of the piston 435 stops I 95 and 91:,

ing and lowering movements of the control box 01 and hence the grinding wheel 54. f'These stops 95 and 91 are 'in the form of depending jaws 'on the lefty dof a pair of bars ,99 and 99, re-

spectivel andbetween whichjaws the control bore |26 in each end. This pump barrel H1 also disk 49 extends'. The bars 98 and 99 are slidably mounted, the latter on the former and both thereof are mounted in a way |00 in the top ofthe housing 30 for endwise sliding movement parallel to the axis of the control head 02. Opening and closing movements areimparted to the stop jaws 99 and 91 by means of a pair of keys'|0| in the form of an X, that work in co-operating ways |02 in the bars 90 and 99. These keys |0| are carried by a spider |03 having a cylindrical body |04 which extends transversely of ithe bars 90 and 99. A long screw shaft |05 extends axially andloosely through the body |00 and said body is held against axial movement oh the shaft |05 by a pair of collars |05 rigidly secured to said shaft atthe ends of the body |04. The shaft |05 is mounted in a front bearing |01 and a rearbi'furv cated bearing |00 on the housing 30. The housing 00 is attened at |09 to aiford clearance for the keys |03. On the front end ofthe shaft |05 is a hand wheel |05"by which the describedconnections may be manually operated to open the stops 99 and 91.

The stop jaws 96 and 91 are progressivelyand automatically opened by a nut-acting ratchet with the screw shaft |05 between the prongs of the bearing |08. A step of rotary movement is,v

Iimparted to the ratchet wheel i |0, simultaneously with that of the ratchet wheel 02 at the limit of the endwise movement of the rack 35 when rotating the control head 32, by a spring-pressed pawl on a pawl carrier ||2. This pawl carrier H2 is bifurcated, straddles the ratchet Wheel ,d2 and the prongs thereof are pivoted on the shaft |05 between the prongs of the bearing |00. The pawl carrier ||2 is yieldingly held on a vertically adjustable stop pin ||3 having screw-threaded en- .gageme'nt with the housing 30, by a coiled spring H4 attached to said carrier and anchored tothe housing 30. The pawl carrier ||2 is lifted from the stop pin to impart a step of movement to the. ratchet wheel ||0, by a laterally projecting lug ||5 on the lower end portion of the rack 3,5. While the shaft |05ls being. moved `endwise to automatically open the stop jaws y and 9i, said l shaft is held against rotation by clamping the divided bearing |01 thereon. By reference to Fig. l14, it will be noted that the bearing |01 is divided at one side of the shaft |05 and provided with a nut-equipped bolt H6 for contracting said bearing on the shaft |05. L

A hydraulic pump barrel ||1 of the type used by the l,navy for gun control is mounted in a jaws 9|, integral with the right-hand end of the 55 V block ||8 on the left-hand end of the-table 22.

As shown, the table 22 has three T-slots 29 and the V-block ||8 has on its bottom at its transf verse center a key ||9 slidably mounted in the central T-slot 29 and aligns said block with the table 22. This V.b1ock ||0 is rigidly secured toy the table 22 by nut-equipped bolts |20 anchored in the two outer T-slots 29 and extends through transversefslots |2| in the base of said block.

The pump barrel ||1 is` rigidly clamped in the V-block -||8 by a flat metal band |22 that extends transversely over said barrel. This band |22 has on its end'portions screw stud extensions |23 that extend through apertures in the V-block ||8 and have nuts and washers |26 applied tothe limiting the rais- 70 lower ends thereof that engage the V,b1ock iii elusive, has an intermediate axial bore |25 for a pump shaft, not shown, and also has a counterthat'extend into the counterbores |26. The diameter of the counterbores |26 is somewhat greater than the distance between the bottom of the two keyways |21. In the face of the pump barrel ||1 is a plurality of circumferentially spaced cylinders |28. These cylinders |28 open into ports |29 in the back of the pump barrel ||1. It will be noted that the distance between the cylinders |28 is not all the same, but a line extending between the longitudinal axes of the two lowermost diametrically opposite cylinders |28 is perpendicular to a vertical plane passing through the longitudinal axis of the bores and the transverse centers of the two keyways hand end of the bed 2| and has on its upper end a crosshead |33, the upper edge of which is horizontal. In aligning the pump barrel ||1, the table 22 is operated to position said barrel with 2,319,582 l Ahas upper anu lower keyways |21 at its bore |25 connections from the hand wheel |05', automatically feed the grinding wheel 54 in the plane thereof toits work. The width of the grinding wheel- 54 is such as to grind a little more than one-half of the width oi' the keyways |21 so that the cuts made by the grinding wheel 54 at the center of the keyways overlap.

Operation The operation of the improved grinder may be briefly described as follows: The table 22 is hydraulically reciprocated, as indicated at 24, in the well known manner, first to project the shaft extension 53 through the bore |25 in the pump the pinsV |30 projecting transversely over the crosshead |33 and the bar |3| is raised t0 engage its crosshead |33 with the pins |30, and the pump barrel ||1 is turned about its axis in the V- block until .both of the pins |30 engage the crosshead |33. The nuts |20are then tightened to clamp the band |22 onto the pump barrel ||1 to rigidly secure the same in the V-block I I6. With barrel |71 and then retract the same. 'I'he sides of the keyways |21 are successively ground by the outer face of the-grinding wheel 54 and the bottoms of saidfkeyways are ground by the periphery thereof. The controlbox 41, which raises and lowers the grinding wheel 54, and the rack 35, which turns the grinding wheel 54 one hundred eighty (180) degrees and thereby reverses the same face for face, are both hydraulically operated and the movements thereof are synchronized with the movement of the hydraulically reciprccated table 22. Lateral and peripheral feeding movements are imparted to the grinding wheel 54 by the rack 35 at the limit of its upward movement when turning the control head 32.

It may be assumed that the rack 35 is in its lowermost position and is holding the control head 32 with its stop member 38 against one of y the stop lugs 39, and that the control boxes 44 the pump cylinder ||1 thus secured to the table ligure, the pump barrel and all parts thereof as.

well as the positioning pins, the bar and its crosshead are given' the same reference numerals and letters as are used in Figs. 2 to 6, inclusive, except that a prime has been placed thereafter. The bar |3I' is mounted for horizontal sliding movement in guides |34 on a bracket |35 secured l tothe bed 2|.

Obviously, the control head 32 and the control boxes 44 and 41 afford a control unit for turning the grinding wheel 54 face for face about the longitudinal axis' of the shaft extension 53 and positioning the same in a vertical plane on either side thereof, for adjusting the grinding wheel 54 laterally in -respect to the projected longitudinal axis of the control head 32, and for raisingand lowering the grinding wheel 54 in respect to said projected axis.

, It is also obvious that the ratchet 1 wheel 82, with the manually operated connections thereto from the hand wheel 8|, or the automatic connections thereto from the rack 35, and the connections from said ratchet wheel to the control disk 45 aiford 'a feed for moving the grinding wheel 54 laterally to its work. 'Ihe stops 8l and 81, which may be manually set by means of the and 41, the shaft and its extension 53 are all in central positions or, in other words, their axes are co-incident with the axis of the control head 32. As heretofore stated, the keyways |21 primarily are undersize and must be ground to a predetermined width and a predetermined depth.

'I'he first step in the operation of my grinder is to manipulate the hand wheel 8| manually to move the control box 44 laterally, by means of the keys and keyways 46, to position the grinding wheel 54 to grind with its outer face say, the left-hand side of the lower keyway |28, and the control box 41 is hydraulically operated and lowered by means of the keys and keyways 48 to position the grinding wheel 54 to v'grind with its periphery the left-hand one-half of the lower keyway |21 and to position the control -box 41 with its control disk 49 against the stop 88. The table 22 is then hydraulically operated to project the. shaft extension 53 through the bore |2'1 in the pump barrel ||1 and thereby feed the grinding wheel 54 to its Work.

The second step in the operation of the grinder is 'to hydraulically operate the control boxA 41, when the grinding `wheel 54 is out of the pump barrel ||1, to lift the same, by means ofthe keys and keyways 48, and position the grinding wheel 64 to grind with its outer face the left-hand side I of the upper keyway |21 and at the same time to grind with its periphery the adjacent one-half of the` bottom of said upper keyway. The distance the control box 41 is raised is determined by the movement of the control disk 45 from ,the stop 86 to the stop 81. 'I'his lifting movement of the control box 41 positions the grinding wheel 54, with theuppermost surface of its periphery exactly the same distance above a horizontal plane, extending from the longitudinal axis of the pump barrel |21, as the lowermost surface of said periphery was below said plane. With the grind- A54 to its work.

The third step i-n the grinding operation is,

after the grinding wheel 5t has been completely withdrawn from this pump barrel H1 during its retracting movement, to hydraulically raise the rack 35 and thereby turn the control head 32 and all parts carried thereby one hundred eighty degrees (180), and position the grinding wheel l54 on the other side of the longitudinal axis of the shaft extension 53 and with its outer face, by which the sides of the keyways |25 are ground, exactly the same distance from said axis as when the other side thereof, plus a lateral feeding imparted to the grinding wheel 54 by-the ratchet wheel 82 and associated parts, which took place lat the limit of the upward movement of the rack 35 when its trip lug 81 lifted the pawl carrier 84 and operated the ratchet Wheel B2. This rotation of the control head 43 positions the grinding wheel 511 to grind the right-hand side and the adjacent one-half of the upper keyway |25. 'Ihe Y table 22 is now again hydraulically operated to project the shaft extension 53 through the bore H25 i-n the pump'barrel ill and feed the grinding wheel 5d to its work. At the same time that the ratchet wheel 82 is indirectly operatedby the rack 35 to feed the grindingwheel 54 laterally, the stops 9E and 9i are separated, a step of movement by the ratchet wheel i l0 actuated by the trip lug l I5 onthe rack 35 while lifting the pawl carrier H2, to permit an increased movement-of the control box d1 and thereby feed'the grinding wheel 54 'in the plane thereof to increase the depth' of cut made thereby.

The fourth and nal step in the operation of,I the grinder is, after the grinding wheel 54 has ing unit including a shaft mounted on the supconnections lfrom the motor to the grinding wheel, means for adjusting the grinding unit to periodically and successively raise and lower the grinding wheel to feed the same in the plane thereof to its work, and other means for periodically and progressively increasing the distance the grinding wheel is raised and lowered by grinding unit relative to the work. V

2. The combination with a support, of a grindport, a grinding wheel journaled `on the shaft.

` an electric motor mounted on the shaft, driving connections from the' motor to the grinding wheel, meansl for adjusting the grinding unit to periodically and successively raise and lower the grinding wheel to feed the same in the plane thereof to its work, and other automatic means for periodically and progressively increasing the distance the grinding wheel is raisedand lowered by the grinding unit relative to the work.

been moved out of the pump barrel H1, to hydraulically operate thecontrol box 41 and lower the same until its control disk 49 engages the stop 95 andV thereby positions the grinding wheel 54 to grind the right-hand side of the keyway |25, the adjacent one-half of its bottom. The table 22 is now again operated to retract the shaftl extension 53, through the bore 9 25 in the pump barrel lll, and feed the grinding wheel 54 to its work. When the grinding wheel is retracted completely out of the pump barrel lil, the rack i 35 is drawing downwardly hydraulically and rotates the 'control head 32 and parts associated therewith one hundred eighty degrees (180), and

returns the grinding wheels 5t to its starting position and completes a cycle of operation of ,the grinder. Obviously, each timev the rack 35 is hydraulically moved vupwardly to rotate the control headA 32, the grinding wheel 54 is fed a step of movement bothl axially andin the plane thereof.

After the grinding wheel 5t is manually positioned to first grind the lefthand side 0f the lower keyway |21 and the adjacent one-half of the bottom thereof, it mayftake one or more cytrol boxvin the outer control box.

cles of operationof the grinder before grinding action actually takes place. It is, ofcourse, evident that the grinding cuts made by 'the outer face and periphery of the grinding wheel 54 are very slight. From the foregoing, it is evident that the invention herein disclosed and claimed is capable of .a large range o f modification within the spirit of the invention.

What I claim is: e l. The combination with a support, of a grinding unit including a shaft mounted on the sup- Y port, a grinding wheel journaled on the' shaft,

3. The combination with a'support, of a grinciwheel, means for adjusting the grinding unit to feed the grinding wheel laterally to its work, and other means for rotating the shaft to successively turn the grinding wheel face for face.

l 4. The combination with a support of a grinding unit mounted on the support including av shaft, aV rotatable grinding wheel v,'lournaled on the shaft for rotation in a plane parallel thereto, the inner face of the grinding wheel being substantially at the axis of the shaft, means for rotating the grinding wheel, and means for rotating the shaft to turn the grinding wheelface for fa'ce. .I

5. The combination with a support of a grinding unit mounted on the support lncludingarotata'ble control head, outer and inner control boxes, a shaft carried by the inner-control box, a grinding wheel journaled on the shaftin a plane parallel thereto, means for rotating the Agrinding wheel, means for periodically rotating the kcontrol head and then reversing the same to turn-the grinding wheel face for face, saidouter control box being mounted in the control head for movement relative thereto to move the grinding'wheel laterally, said inner control box being mounted in the outer control box for movement relative thereto, to raise and lower the grinding wheel in the plane thereof, and separateand independent means for moving the outer control box in the .control head and theinner con- 6. The structure defined in claim 5 which further includes separate and independent means for guiding the outer control box obliquely in the control head and the inner control box obliquely in the outer control box. I A

7.-. The structure dened in claim 5 which 'further includesautomatic means for movingv the outer control box inthe control head to periodir,cally and progressively feed the grinding wheel laterally to itswork.

dened in claim 5 which fury ther includes automatic means forv periodically 8. The structure and progressively increasing the distance the inner control box israised and lowered .to feed the grinding wheel in theplane thereof to itswork.

9. The combinationwith a support, of a. grinding unit mounted on the support including a rotatable control headw outer and inner control an electric motor mounted on the shaft, driving the boxes, and a shaft carried by theinner control -cally rotating the control head and then reversing the same to turn the grinding wheel face for face, including a segment of a ring gear on the control head and a co-operating rack, said outer control box beingv mounted in the control head for movement relative thereto, to move the grinding wheel laterally, said inner control box being mounted in the outer control box for movement relative thereto, to raise and lower the grinding wheel in the plane thereof, and separate and independent means for moving the'outer control box in the control head and for moving the inner control box in the outer control box. Y

' l0. The structure defined in claim 9 which further includes automatic means for periodically and progressively moving the outer control box in the control head laterally to its work.

11. The structure defined in claim 9 which further includes automatic means actuated by the rack for periodically and progressively moving the outer control box in the control head to feed the grinding wheel laterally to its work. y

12. The structure defined in claim 9 which further includes movable stops for limiting the raising and lowering movements of the inner control head, andfautomatic means for periodically and Ato feed the grinding wheelA progressively adjusting the stops to increase feed of the grinding wheel in the plane thereof to its work. y

13. The structure defined in claim 9 which further includes movable 'stops for limiting the raisingand lowering movements Aof the inner control head, and automatic means actuated by the rack for periodically and progressively adjusting the stops to increase feed of the grinding wheel in the plane thereof to its work.

14. The structure defined in claim 9 which further includes separate and independent means for guiding the outer control box obliquely in the control head and the inner control box obliquely in the outer control box.

15. The structure defined in claim 9 in which the longitudinal axis of the shaft is aligned with the corresponding axis of the inner control head and -in which the control heads are primarily positioned with their longitudinal axis coincident with the longitudinal axis of the control head.

16. The combination with a support, of a grind- -ing unit mounted on the support including a ro- -tatable control head, outer and inner control boxes each having a control disk, a shaft-carried by the inner control box, a grinding wheel iour naled on the shaft with its axis perpendicular to the longitudinal axis of said shaft, means for rotating the grinding wheel and reversing the same to turn the grinding wheel face forv face including a segment of a ring gear on the control head and a co-operating rack, said outer con- A trol box being mounted in the control'head for pendent means including jaws for moving the` movement relative thereto, to move the grinding wheel laterally. said inner control box being mounted in the outer control box Aioimovement relative thereto, to raise and lower the grinding wheel in the plane thereof, separate and indeouter control box in the control headand the inner control box in the outer control box, said jaws holding the control disks against axial movements but permitting relative edgewise movements thereof, means including a pair \of stop jaws between which the control disk on the inner control box extends for limiting the raising and lowering movements of the inner control box in the outer control box. t

17. The structure defined inv claim 16 which further includes automatic means actuated by the rack for periodically and progressively moving the outer control box in the control head to feed .the grinding Wheel laterally to its work.

18. The structure defined in claim 16 which further includes automatic means actuated by the rack for periodically and progressively separating the stop jaws to increase the feed of the grinding wheel in the plane thereof to its work. 19. VThe combination with a support, of a grinding unit mounted on the support including a rotatable control head, a'shaft extending axially in the control head and held for rotation therewith, a grinding wheel journaled on the shaft in a plane parallel thereto, means for rotating the grinding wheel, and other means for periodically rotating the control head to turn the grinding Wheel laterally and bodily about the axis of the shaft.

20. The combination with a support, of a grinding unit mounted on the support including a rotatable control head, a shaft extending axially in the control head. a grinding wheel jour- Agrinding unit mounted on the support including a rotatable control head, a shaft extending axial- 1y in the control head, a grinding Wheel journaled on the shaft in a plane parallel thereto, means for rotating the grinding wheel, and means for mounting the shaft in the control head for rotation therewith and for relative adjustment to feed the grinding wheel radially perpendicular. to the axis of the. control head.

22. The combination with a support, of a grinding unit mounted on the support including a rotatable control head, a shaft extending axially in the control head and held for rotation therewith, a grinding wheel journaled on the shaft in a plane parallel thereto, means for rotating the grinding wheel, and automatic means forA periodically rotating the-control head.

23.'The combination with a support, of a grinding unit mounted on the support including a rotatable control head, a shaft extending axially in the control head, held for rotation therewith b ut free for relative endwise reciprocating movement, a 'grinding'.wheeljournaled on the shaft in a plane parallel thereto, means for rotating the grindingwheel, and automatic means for endwise reciprocatingthe shaft.

24. The combination lwith a support, of a grinding unit mounted, on the support including a rotatable control head, a shaft extending axially vin the control head, a grinding wheel journaled on the shaft -in Aa plane parallel thereto, means for rotatingthe grinding wheel, means mounting the shaft on the control head for rotanaled on the shaft in,` a plane parallel thereto. means for rotating the grinding wheel, means mounting the shaft in the control head for rotric motor mounted on the shaft, driving con-4 nections from the motor to the grinding wheel,

and means for moving the grinding unit relative on the shaft in 29. The combination with a normally stationary support, of a rotatable grinding unit mounted on the support, ashaft extending axially through the grinding unit and held for common rotation therewith, a grinding wheel journaled a plane parallel thereto, means for rotating the grinding unit in the support to turn the grinding wheel bodily laterally about the axisA of the shaft to successively position its outer face on opposite sides `of the' axis of the shaft, and other means for'adjusting the grinding unitrlaterally relative to the supportin a plane perpendicular to the plane of the grinding wheel to feed the grinding wheel laterally against a surface of a piece of work.

30. The structure definedinclair'n 29 further including means for adjusting the grinding unit to the support to adjust the shaft radially in a plane perpendicular to the plane of the grinding wheel to feed one face of the grinding wheel against a surface of a piece of work.

27. The combination with normally stationk ary support, of a rotatable grinding unit mounted on the support, a shaft extending axially through the grinding unit and held for common rotation therewith, a grinding wheel journaled on the shaft in a plane parallel thereto, an electric -motor mounted on the shaft, driving connec-` tions from the motor to the grinding wheel, and means for moving the grinding unit relative to the support to adjust the shaft radially in a plane parallel to the plane of the grinding wheel to successively position the periphery of the grinding wheel at diametrically opposite points transversely of the shaft against opposite surfaces of a piece of work.

28. The combination with a normally stationary support, of a rotatable grinding unit mounted on 'the support, a shaft extending axially through the grinding unit and held for common rotation therewith, a grinding wheel journaled v on the shaft in a plane parallel thereto, an electric motor mounted on the shaft, driving connections from the motor to the grinding wheel, and means for moving the grinding unit relative to the support to adjust the shaft radially in a planeparallel to the plane of the grinding wheel to periodically and successively position the periphery of the grinding wheel at diametrically y wheel journaled on the relative to the support in a plane parallel to the plane of the grinding wheel to successively posi-l tion the periphery'of the grinding wheel at diametrically opposite points transversely of the shaft against opposite sur'faces of a piece of work.

3l. The combination with a support, of a grinding unit mounted on the support including a rotatable control head, a'tubular shaft extending axially through the control head and held for common rotation journaled on the shaft at one end thereof, lin a plane parallel thereto and having av driven pulley, an electric motor mounted on the shaft at the other end thereof, a drivlng'puiley encircling the motor 'intermediate of its ends and secured to its amature shaft, a belt extending through the shaft. and arranged to run over the two pulleys. the grinding wheel, the motor and their associated parts being substantially balanced about the longitudinal axis of the means for adjusting the shaf-t radially in the control head ,in planes parallel with and. prpendicular to the plane of the grinding wheel.

. 32. The combination with a normally stationary support, of

'heldfor 'common rotation therewith, a grinding l shaft in ,a plane parallel thereto, means iorl rotating the grinding wheel. and means `for adjusting the shaft radially in the opposite points transversely of the shaft against 'w controlv head to feed the grinding wheel laterally. vopposite surfaces of a piece of work. GUY

B. CARROLL therewith, a grinding wheel shaft, and compound V 

